A major objective of this research is the delineation of the scope, mechanism, and synthetic utility of (3,3) sigmatropic rearrangements of N-vinyl- and N-aryl-O vinylhydroxylamines and their derivatives. This transformation which is formally named as a 1-aza-1'-oxa(3,3) sigmatropic rearrangement has been referred to in our laboratories as the 1'-aza-Claisen rearrangement for convenience. This reaction constitutes a new and potentially useful synthetic operation for carbon-carbon bond formation which gives rise to 1,4-imino ketones or heterocycles resulting from ring closure. The high exothermicity of the process leads to the expectation that such reactions would occur under quite mild conditions. Other important subgoals include the development of suitable methodology for preparing or generating the requisite N-vinyl- and N-aryl-O-vinylhydroxylamines and the application of the reaction to the synthesis of natural products and/or biologically-active compounds. Since the chemical events involved in carcinogenesis by certain polycyclic aromatic compounds are poorly understood, another objective has been the expansion of our knowledge of unsaturated hydroxylamines. It has been proposed that the chemical interaction of the polycyclic hydroxylamine with a heterocyclic base on a DNA molecule might occur via an aza-Claisen or closely related rearrangement. The feasibilty of this idea is to be evaluated with certain model reactions.